How do i generate traffic on a router interface?

[DespoticWolf]

Hi all,

I wanted to know if there was a way to generate traffic on a router interface. In my organization there are often two ISPs on a router and one is used as a backup and so it doesn't show any traffic when i use the command "Show interface G0/0/0 | i rate" but I want to make sure the circuit is usable. I tried ping with the source command but sometimes i do 1000 pings and might get a couple packets. I'm not sure what is happening but I'm guessing ping traffic doesn't really count. Thank you in advance.

-Alex

[MHM Cisco World]

Use ping and specify source

MHM

[M02@rt37]

Hello @DespoticWolf 

You can use IP SLA to generate traffic on the backup ISP link in a more reliable and efficient way than simple ping tests. IP SLA allows you to simulate real application traffic by sending ICMP, TCP, or UDP packets from the router interface to a destination, ensuring that the backup link is functional.

[DespoticWolf]

@MHM Cisco World Thank you for your suggestion. Unfortunately, I've tried that but sometimes it only generates like 5 packets, one-way from 1000 pings idk why but I was hoping there was something was another command or an option

M02@rt37 Thank you for your suggestion. It sounds a little more advanced but unfortunately, I'm not allowed to make configuration changes and was hoping for another simple option, thank you, I will have to try this on my home lab.

[MHM Cisco World]

5 from 1000 meaning that ping with source interface is work 

But why only 5 

Two points

1-CoPP of router

2-policy of ISP prevent this 1000 ping.

How can I make sure 

Debug icmp 

See if router after 5 still send icmp with receive icmp reply 

MHM

[Ramblin Tech]

Some versions of IOS implemented ttcp; if you are lucky, yours does. Ttcp is good for on-demand, diagnostic testing, but not so much for continual monitoring (IPSLA/TWAMP are good for that).

router1#ttcp
transmit or receive [receive]:
perform tcp half close [n]:
receive buflen [8192]:
bufalign [16384]:
bufoffset [0]:
port [5001]:
sinkmode [y]:
rcvwndsize [4128]:
delayed ACK [y]:
show tcp information at end [n]:

ttcp-r: buflen=8192, align=16384/0, port=5001
rcvwndsize=4128, delayedack=yes tcpttcp-r: accept from 192.168.1.2
ttcp-r: 16777216 bytes in 65720 ms (65.720 real seconds) (~249 kB/s)+++
ttcp-r: 7678 I/O calls
ttcp-r: 0 sleeps (0 ms total) (0 ms average)

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

router2#ttcp
transmit or receive [receive]: transmit
Target IP address: 192.168.1.1
perform tcp half close [n]:
send buflen [8192]:
send nbuf [2048]:
bufalign [16384]:
bufoffset [0]:
port [5001]:
sinkmode [y]:
buffering on writes [y]:
show tcp information at end [n]: y

ttcp-t: buflen=8192, nbuf=2048, align=16384/0, port=5001 tcp -> 192.168.1.1
ttcp-t: connect
ttcp-t: 16777216 bytes in 65713 ms (65.713 real seconds) (~249 kB/s) +++
ttcp-t: 2048 I/O calls
ttcp-t: 0 sleeps (0 ms total) (0 ms average)
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Connection is ECN Disabled, Mininum incoming TTL 0, Outgoing TTL 255
Local host: 192.168.1.2, Local port: 44130
Foreign host: 192.168.1.1, Foreign port: 5001
Connection tableid (VRF): 0
Maximum output segment queue size: 50

Enqueued packets for retransmit: 2, input: 0 mis-ordered: 0 (0 bytes)

Event Timers (current time is 0x700EF):
Timer Starts Wakeups Next
Retrans 8981 60 0x704D8
TimeWait 0 0 0x0
AckHold 1 0 0x0
SendWnd 12 0 0x0
KeepAlive 0 0 0x0
GiveUp 0 0 0x0
PmtuAger 0 0 0x0
DeadWait 0 0 0x0
Linger 0 0 0x0
ProcessQ 0 0 0x0

iss: 1053948561 snduna: 1070723174 sndnxt: 1070725778
irs: 1617650442 rcvnxt: 1617650443

sndwnd: 4128 scale: 0 maxrcvwnd: 4128
rcvwnd: 4128 scale: 0 delrcvwnd: 0

SRTT: 1000 ms, RTTO: 1003 ms, RTV: 3 ms, KRTT: 0 ms
minRTT: 0 ms, maxRTT: 1000 ms, ACK hold: 200 ms
uptime: 65719 ms, Sent idletime: 5 ms, Receive idletime: 5 ms
Status Flags: active open
Option Flags: Retrans timeout
IP Precedence value : 0

Datagrams (max data segment is 1460 bytes):
Rcvd: 13369 (out of order: 0), with data: 0, total data bytes: 0
Sent: 12358 (retransmit: 72, fastretransmit: 0, partialack: 0, Second Congestion: 0), with data: 12356, total data bytes: 16777204

Packets received in fast path: 0, fast processed: 0, slow path: 0
fast lock acquisition failures: 0, slow path: 0
TCP Semaphore 0x10D155BC FREE
router2#